HC, you can't purge based on not using a pad in any sequence. Only purge unused samples as you have read in the manual. Post at your peril on the MPC forums
you'll also have to decide if you are using Akai OS or JJ OS as there are 2 separate threads and the 2 factions don't fraternise.
My suggestion: because the 1000 got updates to match the 2500 features, stick to Akai OS.
Cheers,
B